1. Field of the Invention
The present invention relates to drip valves and more particularly to temperature controlled drip valves.
2. Description of the Related Invention
Many fire extinguishing systems that dispense water and/or fire fighting foams, use sprinkler heads to deliver the fire fighting material. The sprinkler heads often contain a temperature sensitive actuator that opens a valve within the sprinkler head when the temperature sensed exceeds a predetermined set-point. The present invention provides a simple but effective valve for these types of sprinkler heads. The valve is also easily adapted for use in drip valve installments for preventing the build-up of freezing or scalding fluid within the system.
U.S. Pat. No. 3,734,191, issued on May 22, 1973 to Johnson, et al., shows a temperature controlled sprinkler head assembly having a spring biased closure. A temperature sensitive actuator controls a simple valve within the sprinkler head. U.S. Pat. No. Re. 29,155 issued on Mar. 22, 1977 to Mears et al., discloses an on-off sprinkler with a valve controlled by a bimetal disc actuator. The actuator has a snap action and hysteresis for providing a thermal delay upon closing the valve. U.S. Pat. No. 4,899,825, issued on Feb. 13, 1990 to Bosoni, et al., describes a fire extinguishing system wherein a foam-water mixture is supplied via a single conduit to a user device. Volumetric pumps proportionally meter fire fighting foam based on the flow of fire fighting water. U.S. Pat. No. 5,183,116, issued on Feb. 2, 1993 to Fleming shows a variable pressure regulator that controls the flow rate of fire extinguishing material to a discharge nozzle. A pressure sensitive valve includes a piston body with an O-ring seal that regulates the flow of the fire extinguishing material based on the pressure of the material.
Other devices related to fire fighting systems, but less related to the valved system of the present invention are known, including U.S. Pat. No. 5,667,017 (atomizer for generating water-mists in fire-fighting systems) issued Sep. 16, 1997 to Hoffman et al.; U.S. Pat. No. 4,805,700 (foam generator adjustable to produce foam having various expansion ratios) issued Feb. 21, 1989 to Hoover; and U.S. Pat. No. 5,575,338 (valve for fire fighting installation) issued Nov. 19, 1996 to Sundholm.
The most pertinent related art device is disclosed in U.S. Pat. No. 5,441,113, issued on Aug. 15, 1995 to Pierce, (the present inventor) and this patent is hereby incorporated by reference. The fire extinguishing system described in this patent uses a sprinkler head having a shuttle valve that is operated by a bimetallic disc. The present invention improves upon this sprinkler head by using a valve having a simpler and more effective sealing arrangement.
None of the above inventions and patents, taken either singularly or in combination, is seen to describe the instant invention as claimed. Thus a sprinkler head solving the aforementioned problems is desired.